There is also the paper craft spectrometer kits sold by the Public Lab. I can’t find the version I bought which included a cheap USB board camera but here is a

There is also the paper craft spectrometer kits sold by the Public Lab. I can’t find the version I bought which included a cheap USB board camera but here is a smartphone version: https://publiclab.org/wiki/papercraft-spectrometer https://publiclab.org/wiki/papercraft-spectrometer